Analog To Voip Gateway

I have a request about the different analog gateway.
I have need to connect 20 analog phone on my 3CX Phone system.
I have see the gateway recommanded by 3CX but none can connect 20 analog phone.
Does anyone have an experience on analog gateways with 20 ports ( or more ) compatible with 3CX ?

You say "gateways" yet talk about connecting phones. A VoIP Gateway generally refers to a device that connects a PBX to a provider, as in a PSTN, ISDN or GSM Gateway, these deal with trunks (FXO ports).

An ATA (Analogue Telephone Adapter) connects analogue sets to a VoIP provider or PBX (FXS ports). There are some devices that contain both, a certain number of ports dedicated to each function.

Many multi-port ATAs will work with 3CX even if they are not recommended, it simply means that there probably won't be any "official" support if you run into issues. It all comes down to how familiar/comfortable you are with VoIP and what sort of price, you can get the device. You may want to consider contacting a 3CX Partner in your area for installation assistance.

- 10 IP phone POE Yealink for which I have to draw cables ( for the administrative office area ) .. => This parts it's ok.

- 20 Analog Phone ( The Home area ) because there is already an existing cable to these phones ( 2 wire cable not Ethernet and it's very difficult and expansive to change cable here ). These 20 phones that communicate in internally only..
It's for these 20 phone that I have need the GATEWAY FXS with 20 ports how it :
http://www.ipandgo.com/fr/passerelles-analogiques/404-patton-sn4118-js-eui.html

but would be better with 20 ports. else I can put 2 PATTON SN4118 and one patton SN4114 but it's not clean.

I have see the Patton 4316 but I don't know if will be ok or not..
http://www.sophiesystems.com/patton-smartnode-4316-multiport-fxo-voip-gateway.aspx